The proposed work aims at the synthesis and physical characterization of biocompatible, hydrophilic, crosslinked elastomers as well as at the evaluation of such materials as swelling, anchoring agents for orthopedic prosthetic devices and as local cartilage replacement materials in arthritic joints. In addition to poly (hydroxyethylmethacrylate) hydrogels, which already have shown promise, two new biomedical materials viz. poly (glycerylmethacrylate) made through new routes and poly (N-hydroxypropylmethacrylamid), will be synthesized. Elastic and quasi elastic lightscattering is used as a probe for the non-randomness of the structure and dynamics of the water swollen elastomers. Unidirectional compression is used to establish heir elasticity behavior. Improvement in their poor ultimate properties (tensile and shear) will be sought by the use of specific fillers. Measurements of swelling and swelling pressures complete the physical characterization needed for the design of useful swelling implants in joints. Polymerization will then be carried out in molds, shaped according to the implant situation in test animals.